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Aug. 28, 1928. 1,682,383

J. KUBLER ELECTRICAL RECTIFYING APPARATUS Filed March 20, 1926 J-W W Patented Aug. 28, 1928.

UNETED srars earanrosrics.

JOHANNEsKuBLER, OF BADEN, SVIITZERLAND, ASSIGNOB. TO AKTDSNGESEALLSCHAFT BROWN BOVERI-& 013., OF BABE); SWITZERLAND; A JOINT-STOCK COMPANY OF SWITZERLAND.

Application filed March 29. 1926.

Thisinventiou relates to apparatus for the rectification of-alternating. to direct current and pertains particularly to rectifiersof the mercury vapour type. It is concerned with the distribution of -the impressed. current among a plur'alityof rcctifiers and a plurality of groups ofreetifiers in such fashion as to enable themto function properly when operating in parallel.

The general object of the invention. is the provision ofan arrangement of apparatus whereby there will be an equal distribution of impressed current among the respective recfifiers )of associated groups, and at the same timepermitthe cutting out of one or more of the. groups without affecting the. voltage of the remaining group or groups. for-the ultimate purposeof maintaining uniformity of voltage in the output of the installation while permitting a desired variation in its current output.

Another-object is' the simplification and reduction in cost of apparatus forthe operation of a plurality of groups of rectifiers. in an installation wherein it may be desirable to vary thecurrent output to meet .var \'ing demands.- v

Other. and furtherobjects will be indicated or pointed out hereinafter or obvious to one skilled in the art upon an understanding of the invention.

In the drawing forming a part of this specification I show diagrammaticallv omarrangement of apparatus embodying the. invention, but the same is presented for illustration onlv and is not to be accorded any interpretation having the effect. of limiting the claims short of the true and most comprehensive scope of the invention in the art.

Thedrawing is a diagrammatic illustration of an installation comprising two groups of mercury vapour rectifiers arranged for operation in parallel.

For the purpose ofbest utilizing the inn pressed energy and obtaining imitormit in the output of asymmetric rectifier-s it is. enstomary to use a plurality of them energized from respective secondary winding o a transformer and delivering their output to the same line. Tn order that the; mar function properly it is necessary that they be supplied with current equa ly. .Tt is apparent that an arrangement. which would give an equal distribution of current when ELECTRICA L RECTIFYING APPARATUS.-

Serial-No. 96 342, and in Gcrmany.April 6,1925.

all of the rectitiers-"lwete wbrltingjwouldi thrown off balanceby the cutting out of some of the rectifiers, with-the result-that there would be asubstantial drop of voltage in those. remaining; in operation; In order to avoid. this without complication .orv dupli' cation of apparatus,- I providean arrangement such-=as .-illus tra.tedby that shownv in the 'drawing-. -Here are illustrated two groups of mercury vapour rectifiers. one group comprising the two reetifiers desigs nated A and B.respectivel;v and thejother group comprising ,those designated, D. and. E respectively. The respective, rectifiers. have the anodes m and:cathodes1L thei-eathodfesof the first group being connected to the positive output line L through the switch -X. and the cathodes of the secondgroup .beingliliewise connected to :that line througha-the switch Yw Both groups ofrectifiers are en? ergized :from -:a transformer T- having the core C. This, transformer is provided with two primary winding-s72 and p?- which are connected .in parallel through the switch; S to the alternating--currentlines-Y .The transformer includesa secondary winding for the rectifier A having the-sections If-and a connected to respective anodes, and asceondary-wvinding for the rectifier B having the sections-I) and I) for the respective anodes. These windings arearranged so that the sectionsv whioht-ake. currentsimulta-neouslyare uniformly distributed over the whole primary winding 22.-so as to fully compensate the same. Likewise. the transformer includes a secondary winding d and r for the rectifier D. and a secondary winding 0 and e for the rectifier E. each of said wi ndings being arranged so that the simultaneously energized sections are'nniformly distrihu te dover the whole of the primary winding 1. connections ofthe secondary [windings the anodes of the first group are through the double switch f. and those to the anodes of the second group through the double switch fl. The middle points 0 and O of all of the secondary windings are connected to the negati e wire L of the. direct current system. It will be seen. therefore, that the secondaries of each group are so arranged that all the winding sections which carry current simultaneously are uniformly distributed over the whole length of their associated primary leakage field will be induced in the transformer. This will have the effect of reducing the voltage on the fully loaded rectitier of the group, While the voltage on the one taking the reduced current will be raised.

The construction permits any group or groups of rectifiers to be cut in or cut out of service without afiectingthe operation of those remaining or disturbing the uniform distribution of current among the rectifiers of the active group. For example, if the switch is opened, the current, except for a small fraction, ceases to flow in the primary winding P, while primary winding P still carries its full load current, and the windings d and d and e and e continue to supply rectifiers D and E without interruption or disturbance. Thus, with a single transformer I am able to supply aplurality of groups of rectifiers and permit variation in the quantity output of the installation as desired, by the cutting in or cutting out of the groups selectively, while maintaining the desired equal distribution of current to the respective rectifiers and the desired uniformity of output voltage.

What I claim is:

1. Rectifying apparatus comprising, in combination, a plurality of groups of rectifiers, a transformer common to and supply ing said groups. said transformer including a plurality of parallel primary windings and secondary windings for the corresponding input electrodes of the respective rectifiers, each of said secondary windings being uniformly distributed over its associated primary winding.

2. Rectifying apparatus comprising, in combination, a plurality of groups of rectifiers, a transformer common to and supplying said groups, said transformer including a plurality of parallel primary windings arranged side by side and secondary windings for the corresponding input electrodes of the respective rectifiers, the sections of said secondary windings which carry current simultaneously being uniformly distributed over their associated primary windings.

3. Rectifying apparatus comprising, in combination, a plurality of roups of rectifiers, an output 'line supplied by said rectifiers in common, means for disconnecting individual groups from said line, a transformer common to and supplying the rectifieis, said transformer comprising parallel primary windings for the respective rectifiers and secondary windings having sections for current of different polarity, the sections of the secondary windings which carry cur rent simultaneously being uniformly distributed over their associated primary windings and compensating same.

4. Rectifying apparatus, comprising, in combination, a'plurality'of groups of rectifiers, the D. C. electrodes of the rectifiers in respective 'roups being'connected,'an out put linesuppl ied by said groups in common, means for disconnecting respective groups from said line, a transformer common to and supplying said groups of rectifiers, said transformer comprising parallel primary windings, onefor each group, and-secondary windings connected to corresponding elec/ trodes of the respective recti'fiers, the simultaneously active secondary windings of each group compensating the primary winding of such group, and means for disconnecting the rectifiers'of respective groups from their secondary windings.

5. Rectifying apparatus comprising, in combination, a plurality of groups of rectifiers each having a lurality of anodes, an output line suppli by said rectifiers in common, and a transformer common to and supplying said groups of rectifiers, said transformer comprising a primary and a secondary winding for each group, each of said secondary windings being divided into sections connected to and energizing respectire anodes of the associated group, the simultaneously energized secondary sections compensating the associated primary windmgs.

In testimony whereof I have hereunto subscribed my name at- Zurich, Switzerland, on the 4th day of March, A. D. 1926.

J OHAN NES KUBLEB. 

